diff --git a/README.md b/README.md
index 9f44e2a..a61fabc 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # Sriracha - Extensible imageboard
+[![GoDoc](https://code.rocketnine.space/tslocum/godoc-static/raw/branch/master/badge.svg)](https://docs.rocketnine.space/code.rocketnine.space/tslocum/sriracha)
 [![Donate via LiberaPay](https://img.shields.io/liberapay/receives/rocketnine.space.svg?logo=liberapay)](https://liberapay.com/rocketnine.space)
 [![Donate via Patreon](https://img.shields.io/badge/dynamic/json?color=%23e85b46&label=Patreon&query=data.attributes.patron_count&suffix=%20patrons&url=https%3A%2F%2Fwww.patreon.com%2Fapi%2Fcampaigns%2F5252223)](https://www.patreon.com/rocketnine)
 
diff --git a/cmd/sriracha/config.go b/cmd/sriracha/config.go
new file mode 100644
index 0000000..88a0f8d
--- /dev/null
+++ b/cmd/sriracha/config.go
@@ -0,0 +1,27 @@
+package main
+
+// AppConfig defines the database configuration. All other configuration
+// options are stored within the database.
+type AppConfig struct {
+	// Driver specifies the database driver to use. By default, the "sqlite"
+	// and "pq" (PostgreSQL) drivers are available. Sriracha may be compiled
+	// with support for any other database driver by adding it to the imports.
+	Driver string
+
+	// DataSource defines the where and how to interface with the database. Its
+	// contents depend on which database driver is in use.
+	//
+	// When using the "sqlite" driver, Datasource may be set to a file path,
+	// typically ending in ".db".
+	//
+	// See https://pkg.go.dev/modernc.org/sqlite#Driver.Open for a full list of options.
+	//
+	// When using the "pq" driver, DataSource may be set as follows:
+	//
+	//   postgres://username:password@localhost:5432/database?sslmode=disable
+	//
+	// See https://pkg.go.dev/github.com/lib/pq for a full list of options.
+	DataSource string
+}
+
+var config = &AppConfig{}
diff --git a/cmd/sriracha/main.go b/cmd/sriracha/main.go
index eaf1756..81a48ac 100644
--- a/cmd/sriracha/main.go
+++ b/cmd/sriracha/main.go
@@ -2,30 +2,33 @@ package main
 
 import (
 	"log"
-	"path/filepath"
 
 	"code.rocketnine.space/tslocum/sriracha"
 	"code.rocketnine.space/tslocum/sriracha/extension"
 
-	// Load SQLite database driver. Multiple drivers may be loaded at the same time.
+	// Load database drivers.
+	_ "github.com/lib/pq"
 	_ "modernc.org/sqlite"
 )
 
 func main() {
 	// Register extensions.
 	// Extensions are processed in the order they are added.
-	databaseName := filepath.Join(".", "db")
 
-	sqlDatabase, err := extension.DatabaseSQL("sqlite", databaseName)
+	// Register database extension.
+	sqlDatabase, err := extension.DatabaseSQL(config.Driver, config.DataSource)
 	if err != nil {
 		log.Fatal(err)
 	}
 	sriracha.AddExtension(sqlDatabase)
 
+	// Register file attachment extensions.
 	sriracha.AddExtension(extension.AttachJPG())
 
+	// Register post handling extensions.
 	sriracha.AddExtension(extension.RenderPost())
 
+	// Run Sriracha.
 	err = sriracha.Run()
 	if err != nil {
 		log.Fatal(err)
diff --git a/extension.go b/extension.go
index 7cb1654..9c00761 100644
--- a/extension.go
+++ b/extension.go
@@ -39,23 +39,28 @@ func extensionName(e Extension) string {
 
 func attach(file io.Reader, size int64, mime string) (*Attachment, error) {
 	for i, ext := range allExtensions {
-		log.Println("DEBUG ATTACH", allExtensionNames[i])
-		a, err := ext.Attach(file, size, mime)
-		if err != nil {
-			return nil, err
-		} else if a != nil {
-			return a, nil
+		if extension, ok := ext.(ExtensionAttach); ok {
+			log.Println("DEBUG ATTACH", allExtensionNames[i])
+			a, err := extension.Attach(file, size, mime)
+			if err != nil {
+				return nil, err
+			} else if a != nil {
+				return a, nil
+			}
 		}
+
 	}
 	return nil, nil
 }
 
 func post(p *Post) error {
 	for i, ext := range allExtensions {
-		log.Println("DEBUG POST", allExtensionNames[i])
-		err := ext.CreatePost(p)
-		if err != nil {
-			return err
+		if extension, ok := ext.(ExtensionPost); ok {
+			log.Println("DEBUG POST", allExtensionNames[i])
+			err := extension.Post(p)
+			if err != nil {
+				return err
+			}
 		}
 	}
 	return nil
diff --git a/extension_attach.go b/extension_attach.go
index a9e92d3..4a4444a 100644
--- a/extension_attach.go
+++ b/extension_attach.go
@@ -2,6 +2,8 @@ package sriracha
 
 import "io"
 
+// ExtensionAttach defines the interface for extensions that handle attaching
+// files when creating a post.
 type ExtensionAttach interface {
 	Extension
 
diff --git a/extension_database.go b/extension_database.go
index 4c9af21..a0846fc 100644
--- a/extension_database.go
+++ b/extension_database.go
@@ -1,5 +1,7 @@
 package sriracha
 
+// ExtensionDatabase defines the interface for extensions that handle storing and
+// retrieving information within a database.
 type ExtensionDatabase interface {
 	Extension
 
diff --git a/extension_post.go b/extension_post.go
index d3097a0..1d6fc1f 100644
--- a/extension_post.go
+++ b/extension_post.go
@@ -1,11 +1,11 @@
 package sriracha
 
+// ExtensionPost defines the interface for extensions that handle creating a post.
 type ExtensionPost interface {
 	Extension
 
-	InsertPost(post *Post) error
-
-	DeletePost(post *Post) error
-
-	RenderPost(post *Post) ([]byte, error)
+	// Post is called when a new post is created. Extensions may modify the
+	// post and apply formatting or other operations on it. All text is
+	// initially HTML-escaped.
+	Post(post *Post) error
 }
diff --git a/go.mod b/go.mod
index 88f275b..f3f0e7f 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,10 @@ module code.rocketnine.space/tslocum/sriracha
 
 go 1.19
 
-require modernc.org/sqlite v1.21.2
+require (
+	github.com/lib/pq v1.10.9
+	modernc.org/sqlite v1.21.2
+)
 
 require (
 	github.com/dustin/go-humanize v1.0.1 // indirect
diff --git a/go.sum b/go.sum
index 0aa7521..50bbcc7 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,8 @@ github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
+github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
+github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-sqlite3 v1.14.16 h1:yOQRA0RpS5PFz/oikGwBEqvAWhWg5ufRz4ETLjwpU1Y=